Field of the Inventions
The present application relates to the field of metrology, and particularly to LiDAR (Light Distance And Ranging) sensors and related devices.
Description of the Related Art
The process for measuring distance and reflectance values for objects within an environment without touching those objects is of great interest to many industries including surveying, architecture, entertainment (character generated effects for movies and video games), construction, forensic and geography applications. Historically to collect accurate distance and reflectance measurements one used photogrammetry techniques, but the process for extracting information from stereo imagery is both time consuming and expensive. Over the past decade advances in Light Detecting and Ranging (LiDAR) technology have enabled practitioners to scan large area surfaces while collecting billions of data points, each with a precise latitude, longitude and elevation (x, y, z) values within the local (relative) coordinate system. The aggregate of the billions of data points is referred to as a point cloud data set. Practitioners will subsequently extract objects from the point cloud and then create three dimensional models. Those models are then used in numerous applications. For example within geographic information systems (GIS) industry, practitioners will frequently integrate Global Positioning System (GPS) data into the point cloud to ‘geo-reference’ it to a global coordinate system. Every data point in a geo-referenced point cloud has an absolute x, y, and z location on the earth's surface.